welcome to hcm, I really appreciate your concern, IS he taking the medications like levodopa for parkinsons? 1. Drugs is a common reason. if You are not taking medication for Parkinson s, but is there any other medication that you are taking? Medications such as anticholinergic drugs can cause extreme dry mouth. Antidepressants, antihistamines, diuretic antihypertensive medications can cause dryness of mouth. 2. Often inadequate hydration, not drinking enough water causes dry mouth. You may suck on ice cubes which will help hydration as well as keeping mouth moist. Frequent small sips of cold water will also help. 3. There are certain artificial saliva preparations available (Biotène Oralbalance gel, Xerotin oral spray) which help in keeping mouth moist. 4. Sugarless candy will promote salivation. This is effective if salivary glands has some function. 5. A medication called Pilocarpine is sometimes used but is usually reserved for most serious cases such as Sjogren s syndrome or dryness as a side effect of radiation therapy. Adequate water intake is essential when taking pilocarpine. 6. For lips, you may use petroleum jelly. 7. Anxiety may cause dryness of mouth. 8. Overall health also has an effect on salivation. Ensure adequate nutrition. Eat food that is to your liking to avoid discomfort. Please let me know if you have any further questions. Thanks. regards.